Production of photographic colour images with heterocyclic developers



United States Patent PRODUCTION OF PHOTOGRAPHIC COLOUR MAGES WITH HETEROCYCLIC DEVELOPERS Willibald Pelz, Koln-Stammheim, Lothar Burgardt, Leverkusen-Bayerwerk, and Ottmar Wahl, Opladen, Germany, assignors to AGFA Aktiengesellschaft No Drawing. Application March 8, 1955 Serial No. 493,044

Claims priority, application Germany March 18, 1954 Claims. ((31. 96-55) The present invention relates to a process for the production of photographic colour images using heterocyclic developing substances and to silver halide developing solutions containing such. substances.

For the photographic production of colour images by the process of colour development, the developers which are used are compounds which, on the one hand, are in a position to reduce the exposed silver halide of the photographic layer and the oxidation products of which, on the other hand, couple with so-called colour couplers to form dyes. At the moment, only a few classes of compounds are known which may be used for carrying this process into effect. p-Aminophenols and preferably p-phenylene diamine derivatives are the only classes of colour developers hithertoused practically for this purpose.

These developers and the colour images produced therewith nevertheless possess various disadvantages. In the first place, the dyes obtained therewith are not pure in the sense of a subtractive colour mixing, since the dyes usually obtained from them not only absorb in the desired range of the spectrum, but also have a more or less strong adsorbing power in ranges of the spectrum where it is not desired. For example an azomethine dyestufi from l-phenyl-3-methyl-pyrazolone-5 and p-dimethyl 'aminoaniline has an undesired absorbing action in the blue part of the spectrum as well as in the desired green part. Moreover, the dyes obtained with the known developers and thus the colour images produced therefrom are of relatively low light-fastness and stability in storage. A further disadvantage is the fact that all dyestuffs obtained on the basis described above are more or less rapidly and irreversibly destroyed by acids. By introduction of substituents, numerous p-phenylene diamine derivatives have been produced which greatly vary in their useful technical properties and the colour shades of the dyes produced therewith. The disadvantages set forth above could not, however, be substantially .overcome in this manner.

It has now been found that compounds of the following general formula (EH-NH;

wherein Z represents the atoms which are necessary for completing a heterocyclic ring, which again may be substituted by different radicals, constitute excellent colour developers for the process of colour development; the heterocyclic ring may in turn be fused with a further substituted, aromatic, heterocyclic or isocyclic ring.

Such developers are, for example, 4-amino-5-pyrazolones, which may be variously substituted in the 1- position and/or the 3-position, for example, by alkyl,

isoalkyl, substituted or unsubstituted aryl, acyl, alkoxy, carboxyl, carbalkoxy, amino, substituted amino, halogen, hydroxyl, heterocyclic radicals, etc., and also 4-amino-5- isoxazolones-3,5,diketopyrazolidines, etc.

These developers correspond in structure to the o 'aminophenols, which have no colour-developing properties. It it all the more surprising that these o-aminoketones, which may be formulated as heterocyclic compounds analogous to o-aminophenol, have colour-developing properties. i

The novel developers are characterised, as regards their photographic properties, by a number of advantages as compared with the known p-phenylene diamine developers.

Thus, the dyes obtained with these developers show improved light-fastness as compared with the ammethine dyestuffs obtained with p-phenylene diamine developers. An additional advantage of this class of developers is that the dyes obtained therewith are not irreversibly destroyed by acids. Moreover, some of the dyes obtained with these developers have a very advantageous absorption for the production of coloured multi-layer images. For example, a dye which is obtained from 3-alkyl-l-p-henyl-pyrazolone- 5 and 3-carbethoxy-4-amino-l-phenyl-pyrazolone-S in the conventional manner by colour-forming development has a very much lower blue absorption than is the case with dyes from p-dimethyl-aminoaniline and the same pyrazolones. Moreover, the shade of the dyes obtained from the same colour coupler and one of the new developers may be varied within wide limits. For example, it is possible to obtain a pure yellow by using l-(2-benzthiazolyl)-3- methyl-4-amino-pyrazolone-5 as developer and the aforementioned coupler.

Moreover, the amount of sulphite in the developer solutions prepared with the novel colour developers may be raised to several times the sulphite concentration which is usual with p-phenylene diamine developers, without causing a reduction of the dye formation. By this means, however, the stability of the prepared developer solution is improved.

In admixture with other silver halide developing sub stances, for example p-dimethyl-aminoaniline, the colour shade corresponding to this novel developer is preserved during the colour development until the said developer is exhausted.

A further advantage of the present compounds is based on the fact that they represent very rapid colour developers, so that it is possible to operate with greatly reduced development times. This applies as regards colour developer solutions which merely contain one of the compounds mentioned herein as colour-developing substance, and also for solutions which contain the said compounds in conjunction with a p phenylene-diamine derivative. Moreover, the developers which are claimed are extraordinarily intensive, so that the sensitivity of the photographic material can be improved when such developers are used, as compared with p-phenylene diamines.

The novel developers also couple intensively to form brilliant colours with compounds with which p-phenylene diamines only couple badly or produce dull colours, for example with fl-naphthols to form green to blue-green dyes or with S-hydroxy-quinolines to form purple dyes. With m-dimethylaminoaniline there are obtained brilliant magenta dyestuffs.

A further advantage of these developers is that they are very soluble in water and alkali, and the very Wide range of readily soluble substitution derivatives are readilyavailable synthetically, generally without the developing properties being modified in an unfavourable manner by the inclusion of the substituents. For example, a free carboxyl group may be introduced into 4-amino-pyrazolones in the 3-position for increasing the solubility in alkali without it being necessary to accept a lowering of the developing power, whereas the developing power of p-phenylene diamine derivatives is in most cases strongly reduced by nuclear substitution with carboxyl groups. The developing substances may also be incorporated into silver halide emulsion layers. These are developed by means of an alkaline solution, whereby the colour couplers are either added to their solution or to the emulsion layer. I

EXAMPLE 1 A photographic silver bromide emulsion, to which 4 stearoyl amino benzoyl acetanilide 3,5 dicarboxylic acid is added as a diffusion-resisting color former is exposed and developed in a developer of the following composition:

The material is rinsed, bleached and fixed in the usual manner, and there is thus obtained an intensive yellow dye image.

The methaue-sulfo-hydrazide of 1-phenyl-4-aminopyrazolone-Scarboxylic acid hydrochloride is obtained as follows:

23.2 g. of 3-carbethoxy-l-phenyl-pyrazolone (90%) are heated to 70 C. with 12 cc. of alcohol, 12 cc. of hydrazine hydrate (80%) are added, the mixture is heated to boiling temperature for 5 hours and stirred into cc. of concentrated HCl and 40 g. of ice, filtered with suction, the filtered substance washed with water, stirred with 100 cc. of water, filtered with suction and the filtered product dried. M.P.: 252254 C.

10.9 g. of the pyrazolone obtained are dissolved in 42.5 cc. of NaOH (5%), 6.3 g. of methane sulfochloride added in drops at -20 C. and the solution is kept alkaline by the addition of NaOH (10%), (alkalinity is determined by means of phenol phthalein) stirred for one hour, filtered and the filtrate precipitated with hydrochloric acid (10%) and filtered with suction. The wet product is dissolved in 50 cc. of NaOH (10%), 3.5 g. of NaNO are added and the mixture is added dropwise to 50 cc. of concentrated HCl and 75 g. of ice at 510 C., filtered with suction, stirred with methanol (50%) and filtered with suction once more. The resulting isonitroso compound is reduced in a manner analogous to the directions in Arch. Pharm., 278 (1940), 330.

EXAMPLE 2 If p octadecenyl succinamino benzoyl acetonenitnle is used as color former and 3-phenyl-4-aminoisoxazolone-hydrochloride is used as color-developing substance in accordance with the process according to Example 1, an intensively lemon-yellow dye image is obtained.

The 3 phenyl 4 amino isoxazolone hydrochloride is obtained as follows:

3-phenyl-isoxazolone-5 prepared as described in Berichte der Deutschen Chemischen Gesellschaft, 24 1891), 502, is treated with nitrous acid according to Berichte, 24, (1891), 142, and reduced as follows:

19 g. of the nitroso compound are reacted in 20 cc. of alcohol and 120 cc. of concentrated HCl at 10-15" C. in portions with tin sponge in a total amount of 24 g., stirred until decolorized, filtered with suction, the filtered substance dissolved in little cold water and precipitated with concentrated HTl.

If the above-said color coupler is replaced by 5-octa- 4 decenyl-succinaminoindazolone a magenta image is obtained.

EXAMPLE 3 If the color former indicated in Example 1 is replaced by a pyrazolone, for example by 1-(4'-phenoxy-3-sulphophenyl)-3-heptadecyl-parazolone-5, and if the color-developing substance is replaced by the hydrochloride of 1-phenyl-3-carbethoxy-4-amino-pyrazolone-5, a brilliant magenta image having high blue transmission is obtained (abs. max. 560 mg).

The 1 phenyl 3 carbethoxy 4 amino pyrazolone-5 can be obtained according to Arch. Pharm., 278. (1940), 330.

EXAMPLE 4 1 (2',4 disulphophenyl) 3 (m' stearoyl-:

aminophenyl)-pyrazolone is used in place of the color former mentioned in Example 1, and the hydrochloride of l-phenyl-4-amino-pyrazolone-3-carboxylic acid amide is used as developer. A magenta image having high blue transmission is obtained.

The 1 phenyl 4 aminopyrazolone (5) 3 carboxylic acid amide is obtained as follows:

20 g. of 1-phenyl-3-carbethoxypyrazolone-(5) are heated with 40 g. of aqueous NH solution (25%) in the autoclave to 100 C. for 6 hours, part of the excess ammonia is removed by releasing pressure and the content of the autoclave is acidified with concentrated HCl after cooling, filtered with suction and the paste obtained is used directly for treatment with nitrous acid.

42 g. of thepaste containing l-phenyl-S-carbonamide pyrazolone-5 (21.8%) are dissolved in 27.5 cc. of NaOH (10% 3.2 g. of sodium nitrite are added and the whole is stirred into a mixture'of 30 cc. of concentrated HCl hydrazide is used as color developer.

and 30 g. of ice at 0 C., filtered with suction and thefiltered substance washed with about 50 cc. of methanol.

10 g. of the isonitroso compound obtained are dissolved in 100 cc. of glacial acetic acid of 40 C., zinc dust is introduced in portions and the solution stirred until decolorized, filtered and hydrogen chloride introduced until precipitation of the hydrochloride is complete, the mixture is filtered with suction and the filtered substance washed with little alcohol.

EXAMPLE 5 with stirring with 26 g. of hydrazine hydrate at 20 C. for 6 hours, stirred with cc. of methanol and filtered with suction. The isonitroso carboxylic acid hydrazide obtained is reduced as described in Example 3.

EXAMPLE 6 A photographic silver halide emulsion layer containing the color coupler of Example 3 is developed in a color developer of the following formula:

CzHsOOC-CCH.NH:

=0 CHg-CH:N

CH2 CH2 The color former is obtained as follows:

31.5 g. of an aqueous hydrazine hydrate solution (35%) is reacted with 16 g. of butadiene sulfone and kept at 75 C. for 30 hours. The major quantity of the water is subsequently removed in vacuum.

15 g. of the resulting sirupy hydrazine are heated with 21 g. of sodium oxalate, 50 cc. of alcohol (50%) and 6.6 cc. of glacial acetic acid to 65 C. for hours, the alcohol is distilled off under reduced pressure, the residue suspended with hydrochloric acid (3%), filtered with suction and the filtered substance recrystallized from dilute acetic acid.

27 g. of the pyrazolone are dissolved in an appropriate quantity of NaOH (5% 7 got sodium nitrite are added and the mixture is added with stirring to 350 cc. of hydrochloric acid (10%) while cooling with ice, filtered with suction and the filter cake substance dried.

12 g. of the nitroso compound are reduced in 12 cc. of alcohol and 48 cc. of concentrated HCl with 4.6 g. of tin sponge, the filtered solution is neutralized with sodium acetate and the precipitate filtered with suction.

By subjecting the above photographic layer to color development by means of this developer a magenta image having the maximum at 550 m is obtained.

EXAMPLE 7 A photographic silver halide emulsion layer is exposed and developed in a developer of the following composition:

After bleaching and fixing an orange-red dye image is obtained.

If the developer contains B-naphthol-5-, or -6-, or -7- sulfonic acid, a green dyestuif image is obtained.

EXAMPLE 3 If 3-cyanoacetylamino-4-N-methyl-N-octadecylamino benzoic acid is used as color coupler in a photographic silver halide emulsion layer and 1-(p'-aminophenyl)-3- carbethoxy-4-aminopyrazolone-5 is used as color developing substance an intensive yellow image is obtained.

The 1 p'-aminophenyl-3-carbethoxy-4-aminopyrazolone-5 is obtained from 42 g. of sodium oxalate, 38 g. of p-nitrophenyl-hydrazine-hydrochloride and 250 cc. of alcohol (50%); the mixture is stirred at 60-70 C. for 3 hours, filtered with suction-after cooling, washed with methanol (50%) and recrystallized from dilute alcohol.

27 g. of the pyrazolone obtained are dissolved in 150 cc. of NaOH (5%), 7.2 g. of sodium nitrite added and dropped at 510 C. into 100 cc. of concentrated hydrochloric acid and 100 g. of ice, the mixture is stirred for one hour, filtered with suction and the filtered substance washed with water until acid-free.

Reduction is carried out by suspending 30.5 g. of the isonitroso compound with 50 cc. of alcohol and 300 cc. of concentrated HCl, adding in potrions 60 g. of tin sponge, stirring for 24 hours, filtering with suction, dissolving the filtered substance in little water and precipitating the product with concentrated HCl.

EXAMPLE 9 A photographic silver halide emulsion layer containing the color coupler of Example 3 is exposed and developed in a developer of the following composition:

1(2CO3 g. N32S03 ..g. 5 Hydroxylaminosulfate g 2 Potassium bromide g 2 1 (2' benzthiazolyl) 3-methyl-4-aminopyrazol'one-(5)chlorohydrate g 3.5 P-Diethylaminoanilinesulfate ..g 2.5 Water up to cc 1000 is obtained. The 1-(2'-benzthiazolyl)-3-methyl-4-amind pyrazolone is prepared as follows:

0.2 mol of hydrazine hydrate is dissolved in 30 cc. of al-' cohol, 0.1 mol of 2-chlorobenzthiazo'le added in drops with stirring at 4050 C., the solution is filtered with suction after cooling and the filtered substance washed with little methanol. 0.1 mol of the hydrazine is heated to boiling temperature for 2 hours with 0.11 mol of acetoacetic ester and 20 cc. of toluene, the mixture filtered with suction after cooling and the filtered substance washed with toluene.

'10 g. of the pyrazolone are dissolved in 250 cc. of dimethyl formamide, 15 cc. of water and 10 cc. of NaOH 10%), a solution of 3.2 g. of sodium nitrite in 5 cc. of Water is added and the mixture introduced into 300 cc. of glacial acetic acid with stirring at 0 C. The precipitating yellow substance is filtered with suction and reduced as described in Example 3.

EXAMPLE 10 A photographic silver halide emulsion layer containing a color coupler obtained by condensation of 0.15 mol of acetone dicarboxylic acid ester and 0.1 mol of 2-(N- methyl-N-octadecylamino)-phenylhydrazine 5 carboxylic acid in cc. of pyridine and precipitation with hydrochloric acid, is developed with 3-carbethoxy-4- aminopyrazolone-S as described in Example 3.

The 3-carbethoxy-4-aminopyrazolone-(5) is prepared as follows:

15 g. of sodium acetate, 79 g. of sodium oxalate (96%) and 63 g. of hydrazine sulfate in 300 cc. of water are heated to boiling temperature while stirring for 6 hours, stirred in the cold overnight, filtered with suction and the filtered substance washed with little water and methanol.

43 g. of the pyrazolone are dissolved at 15 C. in 100 cc. of HCl (1:1), separated from the undissolved portion, and 17 g. of sodium nitrite in 30 'cc; of water are added in drops to the solution at 10l5 C., the precipitating substance is filtered with suction, Washed with'water and dried.

30 g. of the isonitroso compound obtained are hydrogenated in 100 cc. of methanol and 2 g. of Raney nickel at 100 atmospheres and 50 C.', the catalyst is separated off by filtering in the heat, and the filtrate is mixed with excess concentrated HCl, filtered with suction and the precipitating substance washed with alcohol and ether (1:1).

EXAMPLE 11 A color coupler, which is obtained as described below, is added to a photographic silver halide emulsion layer:

11 g. of 1-(4-phenoxy-3'-sulfophenyl)-3-aminopyrazclone-5 (see Konishiroku Review, vol. 5 (1954), No. 2, pages 34-41) are heated to C. for 5 hours with 8 g. of lauroyl acetate and 20 cc. of pyridine, introduced after cooling into 100 cc. of HCl 10%) while stirring, the mixture is filtered with suction, the precipitated substance dried and washed with little acetone.

By developing the photographic layer with a color developer of the formula: 1-phenyl-4-aminopyrazolone- 3-(N-fl-hydroxyethyl)-carboxylic acid amide in the usual manner, a blue-green dye image is obtained.

The l-phenyl 3 (N-fi-hydroxyethylcarbonamide)-4- amino-pyrazolone-S is obtained as follows:

26 g. of l-phcnyl-3-carbethoxypyrazolone-5 (90%), 10 cc. of ethanolamine, and 5 cc. of water are heated to 110 C. for 5 hours, diluted with water and introduced with stirring into hydrochloric acid (10%), filtered with suction and the precipitated substance is recrystallized from methanol (50% The product can be treated Withnitrous acid and reduced according to any of the herein described methods.

EXAMPLE 12 If 3-stearoylamino-u-naphthol-6-sulfonic acid is used as difiusion resistant color coupler and the color developer 1) CH: of Example 11, a blue-green dye image witha maximum N at 650 m is obtained.

EXAMPLE 13 CHaO COCHzCONH An exposed photographic silver halide emulsion layer containing the color coupler of Example 3 as color dea veloping substance, is developed with 1-phenyl-3-(paminophenyl)-4-aminopyrazolone-5. A magenta image is obtained.

The l-phenyl 3 (p-aminophenyl)-4-aminopyrazo- (E) COCH'CN lone-5 is prepared as follows:

0.05 mol of p-nitrobenzoylacetic ester is heated for two hours in 10 cc. of glacial acetic acid and 10 cc. of water with 0.06 mol of oxalate, filtered with suction 1 after cooling and the prec1p1tat1ng substance recrystallized NBC 0 0H from alcohol.

0.05 mol of the nitro compound is dissolved in an appropriate amount of dimethyl formamide, ten times the quantity of glacial acetic acid added and the calculated quantity of finely pulverized sodium nitrite added in (F) portions with stirring, the mixture stirred for 5 hours, I filtered with suction and the resulting nitroisonitroso "00011 N compound is produced as described in Example 4. as

The following table sets out color shades obtained with various color developers and color couplers of the invention. -In the table, the letters A-M refer to color couplers and the numerals I-X to color developers which are identified on the pages following the table. The numbers cited in connection with the color shades are the absorption maxima in m Table A B O D E F maroon yellow Carmine red rod 500.

yellow 450 mu--- orange475--. brick red. brow orange yellow orange465-. red.

orange yellow orange-.-" orange 495. brown yellowdo orange 490..-" red.

dn rln carmlnered.-. orange.

yellowdo orange red.. orange440. o do carmlnered.-- X orange 550.. yellow 440... yellow 435 red 539.

G H I J K L M T purple 56 purple-.- blue 585 blue 590--- blue-green 650. blue-green 640. II purple 555 purple 550. blue 595 blue 585 blue-green 645- blue-green. Ill do do blue 600 do blue-green 650- Do.

purple blue-green 640. purple 555 purple blue 600..- blue 590--- green green. purple 550 blue 575." blue 585.-- blue-green blue-green. yellow orange.-- blue 590-.- blue 59 do Do. yellow 450 red hlm: violet -..d0. D0. red purple purple blue 57 do do Do. purple 545 purple 55 violet 570 In the above table the letters A-M relate to the following components: (A) 0H; Cit-1 2! 60 (G) CuHuC CH1 N I =0 01-1 0 COCH|CONH N OOH ( COOH O H cunucom-o-ooomcomz 0 COOH (3H3 N NHCOCHzCN 5 lHn 7 v i' i N i -SOgH oo-pH-omo 0011 NH I =0 NH Nfi (I) OH ('30 OH H C ON-CuHu (L) Solution according to Example 11 OH NH0 0 C H 11 at 803K The numerals I-X refer to the following color forming developing substances:

What we claim is: I

1. In the process of producing photographic color images by developing an exposed silver halide emulsion with a color forming developer in an alkali-containing bath and in the presence of a color coupler containing a coupling radical selected from the class consisting of reactive methylene and hydroxy aryl groups, which coupler reacts with the oxidation products of the developer to produce stable dyes that form in the portions of the emulsion where development takes place and remain in those portions to give a dye image corresponding to the exposure, the improvement by which the developer is selected from the class consisting of and where Z represents a group that completes a heterocyclic ring selected from the class consisting of pyrazolone-S and isoxazolone rings, thereby increasing the stability of the dyes that are formed.

2. The combination of claim 1, wherein the heterocyclic ring is substituted by a radical selected from the group consisting of alkyl, aryl, acyl, alkoxy, carboxyl, carbalkoxy, amino and hydroxyl radicals.

3. An alkali-containing photographic silver halide developing solution of a color forming developing subwherein Z represents atoms necessary for completing a heterocyclic ring selected from the group consisting of pyrazolone-5 and isoxazolone rings, said solution also containing a color coupler that has a coupling radical selected from the class consisting of reactive methylene and hydroxy aryl groups, said coupler being capable of reacting with the oxidation products of said developing substance to form dyes with improved stability.

4. A photographic silver halide developing solution according to claim 3, wherein the heterocyclic ring is substituted by a radical selected from the group consisting of alkyl, aryl, acyl, alkoxy, carboxyl, carbalkoxy, amino and hydroxyl radicals.

5. In the process of producing photographic color images by developing an exposed silver halide emulsion with a color forming developer in an alkali-containing bath and in the presence of a color coupler having the difiusion-resistant structure of an alkyl chain containing at least 12 carbons, which coupler reacts with the oxidation products of the developer to produce stable dyes that form in the portions of the emulsion where development takes place and remain in those portions to give a dye image corresponding to the exposure, the improvement by which the developer is selected from the class consisting of GEL-NH;

and

/ONH| all C--OH where Z represents a group that completes a heterolone-5 and isoxazolone rings, thereby increasing the stability of the dyes that are formed.

References Cited in the file of this patent UNITED STATES PATENTS 2,163,781 Eggert et al June 27, 1939 2,698,244 Land Dec. 28, 1954 2,704,711 Hanson Mar. 22, 1955 V 19 OTHER REFERENCES Mees: The Theory of The Photographic Process, pages 584-598. The MacMillan Co. Publishers, New York (1954), revised edition. (Copy in Scientific cyclic ring selected from the class consisting of pyrazo- 5 Library.)

UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,895,825 July 21, 1959 Willibald Pelz et a1. It is hereby certified that error appears in the printed specification of the abovenumbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8, lines 21 to 29 inclusive, the right-hand portion of Formula (F) should read as shown below instead of as in the patent: J--CHa I l' C J=O \N/ 0 column 10, lines 48 to 53 inclusive, the structural formula should read as shown below instead of as in the patent:

C-NH:

Signed and sealed this 3rd day of May 1960.

Attest:

KARL H. AXLINE, ROBERT C. WATSON,

Attestz'ng Ofiaer. C'ommissz'oner of Patents. 

1. IN THE PROCESS OF PRODUCING PHOTOGRAPHIC COLOR IMAGES BY DEVELOPING AN EXPOSED SILVER HALIDE EMULSION WITH A COLOR FORMING DEVELOPER IN AN ALKLI-CONTAINING BATH AND IN THE PRESENCE OF A COLOR COUPLER CONTAINING A COUPLING RADICAL SELECTED FROM THE CLASS CONSISTING OF REACTIVE METHYLENE AND HYDROXY ARYL GROUPS, WHICH COUPLER REACTS WITH THE OXIDATION PRODUCTS OF THE DEVELOPER TO PRODUCE STABLE DYES THAT FORM IN THE PORTIONS OF THE EMULSION WHERE DEVELOPMENT TAKES PLACE AND REMAIN IN THOSE PORTIONS TO GIVE A DYE IMAGE CORRESPONDING TO THE EXPOSURE, THE IMPROVEMENT BY WHICH THE DEVELOPER IS SELECTED FROM THE CLASS CONSISTING OF 